As noted hereinabove, the present invention is directed to a container comprising two complementary container pieces which form a container particularly suitable for use in the fast food industry. Containers of this type are well known in the art. In this industry, emphasis is placed on constructing the two-piece tray-type cartons or containers such that they may be easily joined together to enclose an item. An early version of this type of container is set forth in U.S. Pat. No. 3,027,062 issued to Huss et al.
Huss et al. discloses a combination tray and cover adapted to be interlocked with one another to contain an article. Therein, the tray and cover preferably are constructed from blanks of identical size and contour. The side walls of each tray and the cover piece include a locking tab located at the top edge thereof having a male portion delineated by a slit and a counter tab. To interlock the tray and cover, the cover is positioned over the tray so that the interlocking tabs of the two pieces are placed in contact. Thereafter, the tray and cover are rotated relative to one another until the male portions of the interlocking tabs of each piece lockingly engaged with the slits of the other piece. The cover can similarly be removed by twisting in the opposite rotational direction. However, it is noted that this container requires a particular manipulation of the cover with respect to the tray which may result in misalignment of the locking tabs of the two pieces. Additionally, when handled by the consumer, the cover may become inadvertently dislodged from the tray.
In an effort to overcome the aforementioned shortcomings, locking trays of the type illustrated in U.S. Pat. Nos. 4,856,707 issued to Lorenz, 5,160,081 issued to Beales, and 5,188,284 issued to Eisman have been proposed. Each of these locking trays include a cover and tray portion which are formed from substantially identical blanks. Both the cover and tray of each of these references include outwardly extending locking tabs which interfere with similar locking tabs of the other of the tray or cover in order to secure the cover in place with respect to the tray. With the locking tray set forth in U.S. Pat. No. 4,856,707, in order for the tray and cover to be formed of identical blanks, the resultant container must be of a square configuration. Furthermore, with each of the above-noted type locking trays, the extending tabs which extend beyond the confines of the tray or cover are readily susceptible to damage by either bending or tearing of the tabs. If such occurs, it will be difficult if not impossible to interlock the trays in the proposed manner.
In a still further effort to overcome the aforementioned shortcomings, a locking tray of the type set forth in U.S. Pat. No. 5,060,851 issued to Lorenz is utilized wherein a cover and tray are manufactured from similar blanks with a first pair of opposing sidewalls of each piece having an upstanding tab portion extending from the top edge of the central portion of the sidewall and a second pair of opposing sidewalls of each piece including two spaced-apart upstanding portions for receiving an associated tab portion therebetween to interlock the container pieces. While this construction obviates the aforementioned shortcomings associated with the prior containers, this reference continues to falter from the possibility that the interlocking members will not fully interlock with one another resulting in the dislodging of the cover with respect to the tray. Further, if the outer flanges of the cover which are exposed are grasped by the consumer in order to carry a container including hot contents, the cover will be readily dislodged from the tray resulting in the tray dropping with respect to the cover.
A still further effort to overcome aforementioned shortcomings is set forth in U.S. Pat. No. 4,804,137 issued to Hardy and includes a container having a bottom tray and a like tray which is inverted and rotated 90.degree. with respect to the bottom tray to form a lid or cover for the bottom tray. Once positioned over the tray, the cover is adhered in place by extending flanges of both the cover and tray. While this ensures the placement of the cover over the tray, the cover may not be readily removed from the tray to gain access to the contents by the consumer. Additionally, if the container is anything but a square container, the cover and tray cannot be formed from identical blanks. In addition to the use of adhesives, the container of Hardy may include tabs formed in opposed extending flanges of the cover and tray with corresponding slots formed in the other opposing sidewalls of both the cover and tray for receiving the extended tabs of the other of the cover or tray. However, again such a construction requires that the container be of a square nature in order for the container to be formed from identical blanks. Moreover, when assembling the container in the manner set forth by Hardy, it requires that the locking tab and slot be aligned and secured for each of the four side walls of the container. Still further, due to the nature of the tab and slot arrangement of Hardy, the cover if grasped may be inadvertently dislodged from the tray.
The aforementioned shortcomings are further overcome by the containers set forth in each of U.S. Pat. Nos. 4,470,538 issued to Heathcock et al. and U.S. Pat. No. 5,364,018 issued to Carlsson as well as French Patent Publication No. 2659062. Each of these containers include a tray and cover formed of substantially identical blanks with one opposing pair of sidewalls including locking mechanisms for locking the containers together with respect to one another. In each of the disclosed containers, one opposed upstanding sidewall includes a locking tab or tongue while the other opposing sidewall includes an opening for receiving the locking tab. While the container of Carlsson and the French reference include locking tabs and openings which are extensions of the opposing sidewalls and the locking tab and opening of the Heathcock et al. container is formed integral with the sidewall, including an extension, the containers function substantially in an identical manner. Particularly, the container of the French reference and Heathcock et al. form what is commonly known as a clamshell type container requiring the cover and tray to be integrally connected to one another. While the aforementioned containers do form a positive locking tray and cover arrangement, the tray and cover themselves must be oriented and an opposing orientation in order to positively lock the cover in place over the tray. This requires the user to orient the cover in the appropriate manner with respect to the tray. That being, the locking tab of the cover must be oriented with respect to the opening of the tray and the locking tab of the tray must be oriented properly with respect to the opening of the cover. In a fast food type establishment, such a configuration may result in the improper securing of the cover with respect to the tray thus resulting in a cover which may be readily dislodged from the tray inadvertently uncovering the contents of the container or at a minimum requires additional manipulation of the tray and cover to ensure the proper orientation and thus the proper securing of the tray and cover with respect to one another.
Clearly, there is need for a locking container type of arrangement wherein the tray and cover are formed from identical blanks and further wherein the tray and cover may be oriented in either direction with respect to one another and still form a coherent lock between the cover and tray. Moreover, there is a need for a tray and cover arrangement which once secured may be reliably handled in the event that hot contents are placed in the container.